Shoe Upper Structure, Shoe having the Same and Method for Manufacturing Shoe

ABSTRACT

The object is to improve fitting and supporting properties relative to the midfoot region of the foot of the wearer. The upper structure  2  for the shoe  1  includes a stretchable inner upper portion  20  that has a forefoot part F to cover the forefoot region of the foot of the shoe wearer and a midfoot part M to cover the midfoot region of the foot, and an outer upper portion  21  that is less stretchable than the inner upper portion  20  and that is disposed outside the inner upper portion  20  and overlapped with the inner upper portion  20 . In the state of a free length that the inner upper portion  20  is extended without slackening via its own weight when the upper structure  2  is inverted upside down, the inner upper portion  20  has a clearance e relative to the outer upper portion  21  at least at the midfoot part M.

TECHNICAL FIELD

The present invention relates generally to a shoe upper structure for a shoe that can improve fitting and supporting properties not only at a forefoot region but also at a midfoot region of a foot of a shoe wearer, to a shoe having the upper structure, and to a method for manufacturing the shoe.

BACKGROUND ART

U.S. Pat. No. 4,438,574 discloses a sports shoe (10) that has an upper structure comprising a stretchable inner layer (40) and a non-stretchable outer layer (42) at a forepart section (see lines 32-39 of column 4 and FIGS. 1-4). Here, the forepart section designates a toe portion of a foot (see lines 60-63 of column 3).

The above-mentioned US Pat. describes that a limited amount of stretch of the stretchable inner layer (40) causes the inner layer (40) to conform to the shape of the forefoot section of the foot thus obtaining a proper fit (see lines 11-13 of column 3) and the non-stretchable outer layer (42) can prevent the inner layer (90) from stretching out of shape and losing the proper fit at the forepart section of the foot (that is, losing a support property) (see lines 17-21 of column 3).

SUMMARY OF THE INVENTION Objects to be Achieved by the Invention

However, in the above-mentioned upper structure, the inner layer (40) is provided to equally tighten the entire forepart section of the foot and the outer layer (42) is provided to completely overlap with the inner layer (40). Therefore, such an upper structure focuses only on fit and support properties of the forepart section (i.e. the toe portion) of the foot.

Also, in the upper structure, as shown in FIG. 4 of the above-mentioned US Pat., there is formed a large difference in level at a boundary portion between the forepart region comprising the inner layer (40) and the outer layer (42) and the rear part region comprising the woven fabric layer (28, 30) at the rear (i.e. on the right side of the page) of the forepart region. Such a large difference in level restricts a smooth bending at the time of bending of the foot, impedes adhesive and fitting properties relative to the foot, and gives discomfort to a sensitive forepart region.

On the other hand, since the individual difference of the perimeter of the foot is greater at the midfoot part than at the forefoot part of the foot, in order to fit the upper of the shoe according to variations of feet between individuals such as a flat foot, high-arch foot, low-arch foot and the like, the midfoot part is more important than the forefoot part. Also, in sports shoes, especially, indoor sports shoes accompanied by lateral intense movements, a higher supportability is required at the midfoot part than at the forefoot part.

The present invention has been made in view of these circumstances and its object is to provide an upper structure for a shoe that can improve fitting and supporting properties at a midfoot region of a foot of a shoe wearer. Also, the current invention is directed to providing a shoe employing such an upper structure and a method for manufacturing the shoe.

Means of Achieving the Objects

An upper structure for a shoe according to a first aspect of the present invention includes an inner upper portion of a stretchability that is disposed inside the upper structure and that has a forefoot part to cover a forefoot region of a foot of a shoe wearer and a midfoot part to cover a midfoot region of the foot, and an outer upper portion of a less stretchability than the inner upper portion, which is disposed outside the upper structure and overlapped with the inner upper portion. When the upper structure is disposed upside down and the inner upper portion is in the state of a free length in which the upper portion is hung downwardly without slackening via its self-weight, the inner upper portion has a clearance relative to the outer upper portion at least at the midfoot part.

According to the first aspect of the present invention, in wearing the shoe, the inner upper portion of a stretchability stretches in the clearance thereby applying a pressing force to the midfoot region of the foot, thus improving a fitting property relative to the midfoot region. Moreover, since a stretch of the inner upper portion in the clearance is restricted by the outer upper portion of a less stretchability, the outer upper portion can improve a supporting property relative to the midfoot region.

In this case, because the clearance is formed between the inner upper portion and the outer upper portion at least at the midfoot part, the inner upper portion smoothly stretches at the midfoot part, thus enhancing fitting and supporting properties relative to the midfoot region without giving a discomfort to the foot.

An upper structure for a shoe according to a second aspect of the present invention includes an inner upper portion of a stretchability that is disposed inside the upper structure and that has a forefoot part to cover a forefoot region of a foot of a shoe wearer and a midfoot part to cover a midfoot region of the foot, and an outer upper portion of a less stretchability than the inner upper portion, which is disposed outside the upper structure and overlapped with the inner upper portion. When the inner upper portion and the outer upper portion are developed on a plane, a foot-width measurement of the inner upper portion is smaller than a foot-width measurement of the outer upper portion at least at the midfoot part.

According to the second aspect of the present invention, since the foot-width measurement of the inner upper portion is smaller than the foot-width measurement of the outer upper portion at the midfoot part, in wearing the shoe, the inner upper portion of a relatively more stretchability stretches to apply a pressing force to the midfoot region of the foot, thus improving a fitting property relative to the midfoot region. Moreover, since a stretch of the inner upper portion is restricted by the outer upper portion of a less stretchability, the outer upper portion can improve a supporting property relative to the midfoot region.

In this case, because the foot-width measurement of the inner upper portion is smaller than the foot-width measurement of the outer upper portion at least at the midfoot part, the inner upper portion smoothly stretches at the midfoot part, thus enhancing fitting and supporting properties relative to the midfoot region without giving a discomfort to the foot.

An upper structure for a shoe according to a third aspect of the present invention includes an inner upper portion of a stretchability that is disposed inside the upper structure and that has a forefoot part to cover a forefoot region of a foot of a shoe wearer and a midfoot part to cover a midfoot region of the foot, and an outer upper portion of a less stretchability than the inner upper portion, which is disposed outside the upper structure and overlapped with the inner upper portion. When the inner upper portion, the outer upper portion and a last for the upper structure are developed on a plane, a foot-width measurement of the inner upper portion that corresponds to a foot-width measurement of the last is smaller than the foot-width measurement of the last at least at the midfoot part.

According to the third aspect of the present invention, since the foot-width measurement of the inner upper portion is smaller than the foot-width measurement of the last at least at the midfoot part, in wearing the shoe, the inner upper portion of a relatively more stretchability stretches to apply a pressing force to the midfoot region of the foot, thus improving a fitting property relative to the midfoot region. Moreover, since a stretch of the inner upper portion is restricted by the outer upper portion of a less stretchability, the outer upper portion can improve a supporting property relative to the midfoot region.

In this case, because the foot-width measurement of the inner upper portion is smaller than the foot-width measurement of the outer upper portion at least at the midfoot part, the inner upper portion smoothly stretches at the midfoot part, thus enhancing fitting and supporting properties relative to the midfoot region without giving a discomfort to the foot.

A longitudinally extending throat portion may be formed opening in connection with a foot entry of the shoe at a foot dorsum top part of the outer upper portion. When the upper structure is upside down and the opening end edge portion of the throat portion of the outer upper portion is in contact with an external surface of the inner upper portion, there may be formed a clearance at least either between a lateral-side part of the outer upper portion and a lateral-side part of the inner upper portion on a lateral-side of the throat portion, or between a medial-side part of the outer upper portion and a medial-side part of the inner upper portion on a medial-side of the throat portion.

In wearing the shoe, the lateral-side part and/or the medial-side part of the inner upper portion having the clearance formed stretches in the clearance, thereby applying a pressing force to the forefoot region and the midfoot region of the foot, thus improving a fitting property relative to the forefoot region and the midfoot region. Moreover, since a stretch of the lateral-side part and/or the medial-side part of the inner upper portion in the clearance is restricted by the outer upper portion of a less stretchability, the outer upper portion can improve a supporting property relative to the forefoot region and the midfoot region.

A longitudinally extending throat portion may be formed opening in connection with a foot entry of the shoe at a foot dorsum top part of the outer upper portion. When the upper structure is upside down and an opening end edge portion of the throat portion of the outer upper portion is in contact with an external surface of the inner upper portion, in a cross section of the forefoot part and the midfoot part of the upper structure, at least either at a medial-side part or at a lateral-side part of the throat portion, the perimeter extending from a bottom end of an internal surface of the outer upper portion to the opening end edge portion of the throat portion may be longer than the perimeter extending from a bottom end of an external surface of the inner upper portion to a position in contact with the opening end edge portion of the throat portion

In wearing the shoe, the lateral-side part and/or the medial-side part of the inner upper portion having a shorter perimeter stretches in the clearance, thereby applying a pressing force to the forefoot region and the midfoot region of the foot, thus improving a fitting property relative to the forefoot region and the midfoot region. Moreover, since a stretch of the lateral-side part and/or the medial-side part of the inner upper portion in the clearance is restricted by the outer upper portion of a less stretchability, the outer upper portion can improve a supporting property relative to the midfoot region.

A longitudinally extending throat portion may be formed opening in connection with a foot entry of the shoe at a foot dorsum top part of the outer upper portion and a tightening member for tightening the foot may be provided at the throat potion. The inner upper portion may extend circumferentially from a medial-side part through a foot dorsum top part to a lateral-side part at the forefoot part and the midfoot part. In the state that the outer upper portion is tightened through the tightening member and an opening end edge portion of the throat portion of the outer upper portion is in contact with an external surface of the inner upper portion, the inner upper portion may be stretchable inside the outer upper portion.

In wearing the shoe, the inner upper portion stretches inside the outer upper portion, such that thereby the medial-side part, the foot dorsum top part and the lateral-side part of the inner upper portion impart a pressing force to the forefoot region and the midfoot region of the foot, thus further improving a fitting property relative to the forefoot region and the midfoot region. Moreover, since a stretch of the inner upper portion is restricted by the outer upper portion of a less stretchability, the outer upper portion can improve a supporting property relative to the forefoot region and the midfoot region.

The stretchability of the inner upper portion may be greater at the midfoot part than at the forefoot part. In this case, the inner upper portion is easier to stretch at the midfoot part than at the forefoot part, such that thereby the fitting property of the inner upper portion relative to the three-dimensional shape of the midfoot region of the foot can be further enhanced.

The inner upper portion may have a substantially flat surface at a region extending from the forefoot part to the midfoot part. The phrase, “a substantially flat surface” designates a planar surface without unevenness and a difference in level due to overlapping of materials, variations of thicknesses and the like, or a surface that can be regarded as a planar surface. Even in the case that two or more materials or ingredients are connected to one another through sewing and the like, a surface that is composed by so-called a flat sewing such as an abutting-sewing is included in the substantially flat surface.

In this case, the inner upper portion is formed of a substantially flat surface, thus eliminating a level-difference feeling, discomfort and a pressing feeling to the foot and preventing a smooth bending of the foot from being disturbed. Thereby, adhesive and fitting properties relative to the foot can be further improved.

The inner upper portion may include a body part and a stretch part having a stretchability and there may be no difference in level at a boundary part between the body part and the stretch part. In this case, the inner upper portion has no difference in level, thus eliminating a level-difference feeling, discomfort and a pressing feeling to the foot and preventing a smooth bending of the foot from being disturbed. Thereby, adhesive and fitting properties relative to the foot can be further improved.

The inner upper portion may include a body part and a stretch part having a stretchability and the body part may be structured in such a way that a plurality of parts divided in a foot-width direction or a foot-length direction are connected to one another. In this case, when the divided surfaces of the respective parts are convexly or concavely formed and connected to one another, the body part can be formed in a three-dimensional shape. Thereby, the body part can be shaped along the three-dimensional shape of the foot. Also, since the inner upper portion is pre-formed in the three-dimensional shape by the body part prior to wearing the shoe, an entry of the foot of the wearer into an access opening of the shoe is facilitated and wearing of the shoe becomes easy.

A shoe according to the present invention may comprise the above-mentioned upper structure and a sole, and the bottom portion of the upper structure is fixedly attached to the sole.

In a method for manufacturing a shoe according to the present invention, the shoe includes an upper and a sole fixedly attached to a bottom part of the upper, and the upper comprises an inner upper portion having a stretchability, disposed inside the upper structure and having a forefoot part to cover a forefoot region of a foot of a shoe wearer and a midfoot part to cover a midfoot region of the foot, and an outer upper portion having a less stretchability than the inner upper portion, disposed outside the upper structure and overlapped with the inner upper portion.

The manufacturing method may comprise the following steps:

i) a step for preparing the inner upper portion and the outer upper portion;

ii) a step for assembling the upper by sewing the outer upper portion onto an outer periphery edge of the inner upper part;

iii) a step for putting the upper on a last for the shoe to stretch the inner upper portion and fixedly attach a bottom part of the upper to the sole; and

iv) a step for removing the upper from the last to cause the inner upper portion that has been in a stretched state to contract and return to a state prior to the stretched state, such that thereby a clearance is formed between the inner upper portion and the outer upper portion.

According to the present invention, in a manufacturing process, the stretched state of the inner upper portion at the time of wearing the shoe can be confirmed. Also, in wearing the manufactured shoe, the inner upper portion of a stretchability stretches, thereby imparting a pressing force to the forefoot region and the midfoot region of the foot, thus improving a fitting property relative to the forefoot region and the midfoot region. Moreover, since a stretch of the inner upper portion is restricted by the outer upper portion of a less stretchability, the outer upper portion can improve a supporting property relative to the midfoot region.

In the state that the inner upper portion, the outer upper portion and the last are developed on a plane, a foot-width measurement of the inner upper portion that corresponds to a foot-width measurement of the last may be smaller than the foot-width measurement of the last at least at the midfoot part.

In this case, since at least at the midfoot part, the foot-width measurement of the inner upper portion is smaller than the foot-width measurement of the last, the inner upper portion can stretch smoothly and securely at least at the midfoot part, thus enhancing fitting and supporting properties relative to the midfoot region without giving a discomfort to the foot.

Effects of the Invention

As mentioned above, according to the present invention, at the midfoot part, the inner upper portion has a clearance relative to the outer upper portion, or the foot-width measurement of the inner upper portion is smaller than that of the outer upper portion in the developed state of the inner and outer upper portions, alternatively, the foot-width measurement of the inner upper portion corresponding to the foot-width measurement of the last is smaller than the foot-width measurement of the last in the developed state of the inner and outer upper portions and the last. In wearing the shoe, the inner upper portion of a stretchability stretches to impart a pressing force to the midfoot region of the foot, thus improving a fitting property relative to the midfoot region. Moreover, since a stretch of the inner upper portion is restricted by the outer upper portion of a less stretchability, the outer upper portion can improve a supporting property relative to the midfoot region.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a medial side view of a sports shoe (for a right foot) employing an upper structure according to an embodiment of the present invention;

FIG. 2 is a lateral side view of the sports shoe of FIG. 1;

FIG. 3 is a top plan view of the sports shoe of FIG. 1;

FIG. 4 illustrates an inner upper portion and an outer upper portion that constitute the upper structure of FIG. 1 in the state that a shoelace is removed from the sports shoe of FIG. 1;

FIG. 5 illustrates an inner upper portion and an outer upper portion that constitute the upper structure of FIG. 1 in the state that a shoelace is removed from the sports shoe of FIG. 2;

FIG. 6 illustrates an inner upper portion and an outer upper portion that constitute the upper structure of FIG. 1 in the state that a shoelace is removed from the sports shoe of FIG. 3;

FIG. 7 is a cross sectional view of FIG. 6 taken along line VII-VII;

FIG. 8 is a cross sectional view of FIG. 6 taken along line VIII-VIII;

FIG. 8A is a cross sectional view of FIG. 3 taken along line VIIIA-VIIIA;

FIG. 9 is a cross sectional view of FIG. 6 taken along line IX-IX;

FIG. 9A is a cross sectional view of FIG. 3 taken along line IXA-IXA;

FIG. 10 schematically illustrates the upper structure of FIG. 4;

FIG. 11 schematically illustrates the upper structure of FIG. 5;

FIG. 12 illustrates the upper structure of FIG. 10 along with a bone structure of a foot;

FIG. 13 illustrates the upper structure of FIG. 11 along with a bone structure of a foot;

FIG. 14 is a cross sectional view of FIG. 10 taken along line XIV-XIV;

FIG. 15 is a developed view in which the inner upper portion and the outer upper portion that constitute the upper structure of FIG. 1 are developed on a plane;

FIG. 16 illustrates a variant of the inner upper portion of FIG. 15;

FIG. 17 illustrates another variant of the inner upper portion of FIG. 15;

FIG. 18 illustrates a variant of the upper structure of FIG. 15;

FIG. 19 illustrates another variant of the upper structure of FIG. 15;

FIG. 20 illustrates still another variant of the upper structure of FIG. 15;

FIG. 21 illustrates a variant of FIG. 8;

FIG. 22 is a developed view in which respective lateral-side parts of the inner and outer upper portions and the last are developed on a plane, illustrating a further variant of the upper structure of FIG. 15;

FIG. 23 is a developed view in which respective medial-side parts of the inner and outer upper portions and the last are developed on a plane, illustrating a further variant of the upper structure of FIG. 15;

FIG. 24 is a developed view in which respective medial and lateral-side parts of the inner and outer upper portions of the upper structure of FIGS. 22, 23 and the last are developed on a plane and disposed oppositely to one another, illustrating the inner and outer upper portions in the state prior to sewing;

FIG. 25 is a cross sectional view of the forefoot part in the state that the upper structure of FIG. 24 is put on the last after sewing of the inner and outer upper portions of the upper structure, which corresponds to FIG. 7 in the above-mentioned embodiment;

FIG. 26 is a cross sectional view of the midfoot part in the state that the upper structure of FIG. 24 is put on the last after sewing of the inner and outer upper portions of the upper structure, which corresponds to FIG. 8 in the above-mentioned embodiment;

FIG. 27 is a developed view in which respective lateral-side parts of the inner and outer upper portions and the last are developed on a plane, which illustrates a still further variant of the upper structure of FIG. 15 and corresponds to FIG. 22; and

FIG. 28 is a developed view in which respective medial-side parts of the inner and outer upper portions and the last are developed on a plane, which illustrates a still further variant of the upper structure of FIG. 15 and corresponds to FIG. 23.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will now be described hereinafter based on the accompanying drawings. FIGS. 1 to 15 show an upper structure according to an embodiment of the present invention and a sports shoe employing the upper structure. Here, an indoor shoe for ball games such as volleyball, handball or the like is taken for an example as a sports shoe. FIGS. 1 to 6 are external views of the shoe (for a right foot), FIGS. 7 to 9A are cross sectional views of the shoe, FIGS. 10 to 13 are schematic views of the upper structure of the shoe, FIG. 14 is a cross sectional view of FIG. 10 taken along line XIV-XIV, and FIG. 15 is a developed view of the upper structure.

In the following explanations, “upward (upper side/top/upper)” and “downward (lower side/bottom/lower)” designate an upward direction and a downward direction, respectively, or vertical direction of the shoe, “forward (front side/front/anterior)” and “rearward (rear side/rear/posterior)” designate a forward direction and a rearward direction, respectively, or longitudinal direction of the shoe, and “a width or lateral direction” designates a crosswise direction or transverse direction of the sole. For example, when FIG. 1, or a side view of the shoe, is taken as an example, “upward” and “downward” generally designate “upward” and “downward” of FIG. 3, respectively, “forward” and “rearward” generally designate “left” and “right” of FIG. 3, respectively, and “a width direction” generally designates “out of the page” and “into the page” in FIG. 3, respectively.

As shown in FIGS. 1 to 3, Shoe 1 comprises an upper structure 2 that extends along the entire length of the shoe 1 to cover an entire foot of a shoe wearer and a midsole 3 that is fixedly attached to a bottom portion of the upper structure 2. In the drawings, reference characters H, M and F designate a heel part, a midfoot part, and a forefoot part of the shoe 1, respectively, which correspond to a heel region, a midfoot region (or a plantar arch region) and a forefoot region of the foot of the wearer.

The upper structure 2 includes an inner upper portion 20 disposed inside the upper structure 2 and an outer upper structure 21 disposed outside the upper structure 2 and overlapped with the inner upper portion 20. In this exemplification, the inner upper portion 20 comprises a tongue of the shoe 1. On top of the outer upper portion 21, there are formed a foot entry 10 and a longitudinally extending throat portion 10 a connecting with the foot entry 10 and extending forwardly at a foot dorsum top part. A shoelace 11 as a tightening member of the shoe 11 is inserted into eyelets 2 a formed on opposite side edge portions of the throat portion 10 a. An outsole 4 having a floor-contact (or ground-contact) surface to contact the floor is fixedly attached to a bottom surface of the midsole 3. The midsole 3 and the outsole 4 constitute a sole of the shoe 1.

As shown in FIGS. 4 to 6, the inner upper portion 20 covers the throat portion 10 a of the outer upper portion 21 from below and has a portion functioning as a tongue of the shoe 1. The inner upper portion 20 extends further forwardly beyond the throat portion 10 a to a tip toe and lower ends of medial and lateral sides (see dotted lines of the drawings) and has the forefoot part F and the midfoot part M that respectively cover the forefoot region and the midfoot region of the foot. The inner upper portion 20 includes a body portion 20A disposed to cover a generally entire foot dorsum region and a stretch portion 20B disposed below the body portion 20A and having a stretchability. An upper end 20 b of the stretch portion 20B is integrally connected with a lower end 20 a of the body portion 20A. The inner upper portion 20 has the stretch portion 20B, thus having a stretchability as a whole. To the contrary, the outer upper portion 21 has no stretch portion, such that thereby stretchability of the outer upper portion 21 is lower than stretchability of the inner upper portion 20.

A rear-side end 20C of the inner upper portion 20 extends diagonally downwardly toward a lower end of the heel part H. In this exemplification, the stretch portion 20B is provided as a generally triangular region having an apex on the rear-side end 20C. The upper end 20 b of the stretch portion 20B and the lower end 20 a of the body portion 20A extend diagonally downwardly toward the front. Respective lower ends of the body portion 20A and the stretch portion 20B are fixedly attached to the midsole 3. A rearmost end 20Bb of the stretch portion 20B is disposed at a lower-end position of the heel part H.

FIG. 7 is a cross sectional view of FIG. 6 taken along line VII-VII, showing a cross section of a toe part with no stretch portion 20B provided at the inner upper portion 20. Here, the shoe 1 is shown upside down (that is, the soles 3, 4 are disposed upside). As shown in FIG. 7, a lower end 20 t of the body portion 20A of the inner upper portion 20 is fixedly attached to a lower end 21 t of the outer upper portion 21 through sewing and the like. The respective ends 20 t, 21 t are fixedly attached to the midsole 3 and an insole board 30 disposed above the midsole 3 through bonding, sewing and the like. Also, the outer upper portion 21 is overlapped with the body portion 20A of the inner upper portion 20, but the outer upper portion 21 is separated from the body portion 20A of the inner upper portion 20 except for the lower end 21 t of the outer upper portion 21 and the lower end 20 t of the body portion 20A.

In the upside-down state shown in FIG. 7, the inner upper portion 20 (and the outer upper portion 21) is disposed at a free length in which the inner upper portion 20 (and the outer upper portion 21) extends vertically downwardly (i.e. in a downward direction of FIG. 7) via its self-weight without slackening. At this juncture, there is formed a clearance e between an external surface 20 s of the inner upper portion 20 and an internal surface 21 s of the outer upper portion 21.

Here, a perimeter of the external surface 20 s of the inner upper portion 20 (that is, a circumferential length measured along the external surface 20 s from one lower end 20 t as a starting end to the other lower end 20 t as a terminal end) is set to 20L. Similarly, a perimeter of the internal surface 21 s of the outer upper portion 21 (that is, a circumferential length measured along the internal surface 21 s from one lower end 21 t as a starting end to the other lower end 21 t as a terminal end) is set to 21L. At this time, an inequality,

20L<21L

is satisfied. Thereby, the inner upper portion 20 is stretchable inside the outer upper portion 21. Also, in this case, preferably, an inequality,

0.5×21L<20L<0.95×21L

is satisfied. That is, the perimeter of the external surface 20 s of the inner upper portion 20 is greater than 50% of the perimeter of the internal surface 21 s of the outer upper portion 21 and smaller than 95% of the perimeter of the internal surface 21 s of the outer upper portion 21. Because under 50%, tightening of the toe portion of the foot is too strong, whereas over 95%, adequate adhesion to the toe portion of the foot cannot be obtained.

FIG. 8 is a cross sectional view of FIG. 6 taken along line VIII-VIII, illustrating a cross section through the throat portion 10 a at a position having no stretch portion 20B of the inner upper portion 20 provided at the forefoot part F and showing the shoe 1 upside down as with FIG. 7. As shown in FIG. 8, the lower end 20 t of the body portion 20A of the inner upper portion 20 is fixedly attached through sewing and the like to respective lower ends 21 ₁t, 21 ₂t of a medial-side part 21 ₁ and a lateral-side part 21 ₂ disposed on opposite sides of the throat portion 10 a of the outer upper portion 21. The respective lower ends 20 t, 21 ₁t, 21 ₂t are fixedly attached to the midsole 3 and the insole board 30 disposed above the midsole 3 through bonding, sewing and the like. Also, the medial-side part 21 ₁ and the lateral-side part 21 ₂ of the outer upper portion 21 are overlapped with the body portion 20A of the inner upper portion 20, but the outer upper portion 21 is separated from the body portion 20A of the inner upper portion 20 except for the lower end 21 ₁t of the medial-side part 21 ₁, the lower end 21 ₂t of the lateral-side part 21 ₂ and the lower end 20 t of the body portion 20A.

In the upside-down state shown in FIG. 8, the inner upper portion 20 (and the medial-side part 21 ₁ and the lateral-side part 21 ₂ of the outer upper portion 21) is disposed at a free length in which the inner upper portion 20 (and the medial-side part 21 ₁ and the lateral-side part 21 ₂ of the outer upper portion 21) extends vertically downwardly (i.e. in a downward direction of FIG. 8) via its self-weight without slackening. At this juncture, there is respectively formed a clearance e₁, e₂ between the medial-side and lateral-side parts 21 ₁, 21 ₂ of the outer upper portion 21 and the inner upper portion 20.

FIG. 9 is a cross sectional view of FIG. 6 taken along line IX-IX, illustrating a cross section through the throat portion 10 a at a position having the stretch portion 20B of the inner upper portion 20 provided at the midfoot part M and showing the shoe 1 upside down as with FIG. 8. As shown in FIG. 9, the lower end 20 t of the stretch portion 20B of the inner upper portion 20 is fixedly attached through sewing and the like to the respective lower ends 21 ₁t, 21 ₂t of the medial-side part 21 ₁ and the lateral-side part 21 ₂ disposed opposite sides of the throat portion 10 a of the outer upper portion 21. The respective lower ends 20 t, 21 ₁t, 21 ₂t are fixedly attached to the midsole 3 and the insole board 30 disposed above the midsole 3 through bonding, sewing and the like. Also, the medial-side part 21 ₁ and the lateral-side part 21 ₂ of the outer upper portion 21 are overlapped with the body portion 20A of the inner upper portion 20, but the outer upper portion 21 is separated from the body portion 20A (and the stretch portion 20B) of the inner upper portion 20 except for the lower end 21 ₁t of the medial-side part 21 ₁, the lower end 21 ₂t of the lateral-side part 21 ₂ and the lower end 20 t of the stretch portion 20B.

In the upside-down state shown in FIG. 9, the inner upper portion 20 (and the medial-side part 21 ₁ and the lateral-side part 21 ₂ of the outer upper portion 21) is disposed at a free length in which the inner upper portion 20 (and the medial-side part 21 ₁ and the lateral-side part 21 ₂ of the outer upper portion 21) extends vertically downwardly (i.e. in a downward direction of FIG. 9) via its self-weight without slackening. At this juncture, there is respectively formed a clearance e₁, e₂ between the medial-side and lateral-side parts 21 ₁, 21 ₂ of the outer upper portion 21 and the inner upper portion 20.

As above-mentioned, according to the present embodiment, in a free-length state that the inner upper portion 20 extends vertically downwardly via its self-weight without slackening with the shoe 1 (and thus the upper structure 2) disposed upside down, the inner upper portion 20 has a clearance e, e₁, e₂ relative to the outer upper portion 21 at a region extending from the forefoot part F to the midfoot part M.

FIG. 8A is a cross sectional view of FIG. 3 taken along line VIIIA-VIIIA, corresponding to FIG. 8. FIG. 8A shows the state in which the shoelace 11 is inserted into the eyelets 2 a in FIG. 8. As shown in FIG. 8A, in the state that the shoelace 11 is provided, the upper end 21 ₁t′ of the medial-side part 21 ₁ of the outer upper portion 21 at the throat portion 10 a is in contact with or disposed immediately adjacent the external surface 20 s of the inner upper portion 20. Likewise, the upper end 21 ₂t′ of the lateral-side part 21 ₂ of the outer upper portion 21 at the throat portion 10 a is in contact with or disposed immediately adjacent the external surface 20 s of the inner upper portion 20. In this case as well, there is respectively formed a clearance e₁, e₂ between the medial-side and lateral-side parts 21 ₁, 21 ₂ of the outer upper portion 21 and the inner upper portion 20.

At this time, the perimeter of the internal surface 21 ₁s of the medial-side part 21 ₁ of the outer upper portion 21 (that is, the circumferential length measured along the internal surface 21 ₁s from one lower end 21 ₁t as a starting end to the other upper end 21 ₁t′ as a terminal end) is set to 21 ₁L. The corresponding perimeter of the external surface 20 s of the inner upper portion 20 (that is, the circumferential length measured along the external surface 20 s from one lower end 20 t as a starting end to the position as a terminal end at which the upper end 21 ₁t′ of the medial-side part 21 ₁ of the outer upper portion 21 is in contact with the external surface 20 s of the inner upper portion 20, or the horizontal projection position of the upper end 21 ₁t′ onto the external surface 20 s is set to 20 ₁L. An inequality,

20₁ L<21₁ L

is satisfied.

Similarly, the perimeter of the internal surface 21 ₂ s of the lateral-side part 21 ₂ of the outer upper portion 21 (that is, the circumferential length measured along the internal surface 21 ₂s from one lower end 21 ₂t as a starting end to the other upper end 21 ₂t′ as a terminal end) is set to 21 ₂L. The corresponding perimeter of the external surface 20 s of the inner upper portion 20 (that is, a circumferential length measured along the external surface 20 s from one lower end 20 t as a starting end to the position as a terminal end at which the upper end 21 ₂t′ of the lateral-side part 21 ₂ of the outer upper portion 21 is in contact with the external surface 20 s of the inner upper portion 20, or the horizontal projection position of the upper end 21 ₂t′ onto the external surface 20 s is set to 20 ₂L. An inequality,

20₂ L<21₂ L

is satisfied.

Thereby, the inner upper portion 20 is stretchable inside the medial-side part 21 ₁ and the lateral-side part 21 ₂ of the outer upper portion 21.

FIG. 9A is a cross sectional view of FIG. 3 taken along line IXA-IXA, corresponding to FIG. 9. FIG. 9A shows the state in which the shoelace 11 is inserted into the eyelets 2 a in FIG. 9. As shown in FIG. 9A, in the state that the shoelace 11 is provided, the upper end 21 ₁t′ of the medial-side part 21 ₁ of the outer upper portion 21 at the throat portion 10 a is in contact with or disposed immediately adjacent the external surface 20 s of the inner upper portion 20. Likewise, the upper end 21 ₂t′ of the lateral-side part 21 ₂ of the outer upper portion 21 at the throat portion 10 a is in contact with or disposed immediately adjacent the external surface 20 s of the inner upper portion 20. In this case as well, there is respectively formed a clearance e₁, e₂ between the medial-side and lateral-side parts 21 ₁, 21 ₂ of the outer upper portion 21 and the inner upper portion 20.

At this time, the perimeter of the internal surface 21 ₁s of the medial-side part 21 ₁ of the outer upper portion 21 (that is, the circumferential length measured along the internal surface 21 ₁s from the lower end 21 ₁t as a starting end to the upper end 21 ₁t′ as a terminal end) is set to 21 ₁L. The corresponding perimeter of the external surface 20 s of the inner upper portion 20 (that is, the circumferential length measured along the external surface 20 s from the lower end 20 t as a starting end to the position as a terminal end at which the upper end 21 ₁t′ of the medial-side part 21 ₁ of the outer upper portion 21 is in contact with the external surface 20 s of the inner upper portion 20, or the horizontal projection position of the upper end 21 ₁t′ onto the external surface 20 s) is set to 20 ₁L. An inequality,

20₁ L<21₁ L

is satisfied.

Similarly, the perimeter of the internal surface 21 ₂ s of the lateral-side parts 21 ₂ of the outer upper portion 21 (that is, the circumferential length measured along the internal surface 21 ₂s from the lower end 21 ₂ t as a starting end to the upper end 21 ₂t′ as a terminal end) is set to 21 ₂L. The corresponding perimeter of the external surface 20 s of the inner upper portion 20 (that is, the circumferential length measured along the external surface 20 s from one lower end 20 t as a starting end to the position as a terminal end at which the upper end 21 ₂t′ of the lateral-side part 21 ₂ of the outer upper portion 21 is in contact with the external surface 20 s of the inner upper portion 20, or the horizontal projection position of the upper end 21 ₂t′ onto the external surface 20 s) is set to 20 ₂L. An inequality,

20₂ L<21₂ L

is satisfied.

Thereby, the inner upper portion 20 is stretchable inside the medial-side part 21 ₁ and the lateral-side part 21 ₂ of the outer upper portion 21.

The body portion 20A of the inner upper portion 20 may be formed of artificial leather, synthetic leather, layer bonding of thermoplastic resin and mesh materials of lower stretchability, and the like. The stretch portion 20B may be formed of materials of higher stretchability that includes elastic fibers such as spandex (i.e. polyurethane elastic yarn) and the like. The outer upper portion 21 may be formed of artificial leather, synthetic leather, mesh materials of lower stretchability, and the like.

The midsole 3 may be formed of a soft elastic material, more specifically, thermoplastic synthetic resin or its foamed resin such as ethylene-vinyl acetate copolymer (EVA) and the like, thermosetting synthetic resin and its foamed resin such as polyurethane (PU) and the like, alternatively, rubber material and foamed rubber such as butadiene rubber, chloroprene rubber and the like. The outsole 5 may be formed of a hard elastic material, more specifically, thermoplastic resin such as thermoplastic polyurethane (TPU), polyamide elastomer (PAE) and the like, thermosetting resin such as epoxy resin and the like, or solid rubber.

Hear, FIGS. 10 and 11 show schematic views of FIGS. 4 and 5. In FIGS. 10 and 11, the midsole 3 and the outsole 5 are not shown and only the upper structure 2 is shown. In the drawings, the solid line indicates the inner upper portion 20, the dash-and-dot line indicates the outer upper portion 21, and the gray region indicates the stretch part 20B of the inner upper portion 20.

FIGS. 12 and 13 show the state in which the bone structure of the foot is introduced into FIGS. 10 and 11, respectively. In FIGS. 12 and 13, the reference character MT designates the metatarsus, CmB the cuneiform bone, NB the navicular bone, CdB the cuboid bone, TA the talus, and CA the calcaneus, respectively. Also, the reference character LF designates the Lisfranc's joint (or tarsometatarsal joint), and TT the Chopart joint (or Transverse tarsal joint).

As shown in FIG. 12, on the medial side of the foot, the stretch portion 20B is disposed at least at a region extending from the base or proximal end part of the metatarsus MT through the cuneiform bone CmB, the navicular bone NB and the talus TA to the calcaneus CA. Also, the upper end 20 b of the stretch portion 20B intersects at lease the Chopart joint TT, alternatively, both the Lisfranc's joint LF and the Chopart joint TT.

As shown in FIG. 13, on the lateral side of the foot, the stretch portion 20B is disposed at least at a region extending from the base or proximal end part of the metatarsus MT through the cuboid bone CdB to the calcaneus CA. Also, the upper end 20 b of the stretch portion 20B crosses the cuboid bone CdB and intersects at lease the Chopart joint TT, alternatively, both the Lisfranc's joint LF and the Chopart joint TT.

FIG. 14 is a cross sectional view of FIG. 10 taken along line XIV-XIV, showing the cross section of the inner upper portion 20 at the midfoot part M and the heel part H. As shown in FIG. 14, the body portion 20A and the stretch portion 20B are coupled to one another by butting and sewing respective ends of the contraposed end surfaces of the body portion 20A and the stretch portion 20B. Such a butt-seaming generates no difference in level and unevenness due to overlapping of the materials at a boundary portion between the body portion 20A and the stretch portion 20B. Also, on both of the respective internal surfaces 20 s′ and the respective external surfaces 20 s of the body portion 20A and the stretch portion 20B, there are no difference in level and unevenness due to overlapping of the materials, variation of thickness and the like. The body portion 20A and the stretch portion 20B are formed of a substantially flat surface (that is, a planar surface or a surface regarded as a flat shape) from the forefoot part F through the midfoot part M to the heel part H and also from the medial side through the top foot dorsum to the lateral side at the respective parts.

FIG. 15 is a developed view of the inner upper portion 20 and the outer upper portion 21 composing the upper structure 2, in which the inner upper portion 20 and the outer upper portion 21 are developed on the same plane. For illustration purposes, the inner upper portion 20 is shown in the solid line and the outer upper portion 21 is shown in the dash-and-dot line. In the drawing, the reference characters w₁, w₂ designate the measurement of the developed inner upper portion 20 in the foot-width or lateral direction and the reference characters W₁, W₂ designate the measurement of the developed outer upper portion 21 in the foot-width direction. The same subscript indicates the same position. That is to say, the reference characters w₁, W₁ designate the foot-width measurement of the same position at the forefoot part F and the reference characters w₂, W₂ designate the foot-width measurement of the same position at the midfoot part M. In the drawing, for illustration purposes, the foot-width direction of the inner upper portion 20 and the foot-width direction of the outer upper portion 21 at the same position are shown with a small gap.

As can be seen from FIG. 15, from the forefoot part to the midfoot part, inequalities,

w ₁ <W ₁.

w ₂ <W ₂

are satisfied. The foot-width measurement of the inner upper portion 20 is smaller than the foot-width measurement of the outer upper portion 21.

Preferably, w₂ and W₂ satisfies the following relational expression;

0.5×W ₂ <w ₂<0.95×W ₂

That is, the foot-width measurement of the inner upper portion 20 is greater than 50% of the foot-width measurement of the outer upper portion 21 and smaller than 95% of the foot-width measurement of the outer upper portion 21. Because under 50%, tightening of the midfoot region of the foot is too strong, whereas over 95%, adequate adhesion to the midfoot region of the foot cannot be obtained. In this preferred embodiment, an equation,

w ₂=0.80×W ₂

is satisfied at the position of 0.2×L forwardly from the heel rear end wherein the entire length of the upper structure 2 is L.

Also, coefficient of extension or stretchability of the inner upper portion 20 is determined according to JIS L 1096 “Testing methods for woven and knitted fabrics” Generally, when the test piece of a predetermined length is set at a tensile testing machine, the tensile load is applied to the test piece, thereafter a gauge length (after loading) L₁ of the predetermined distance L₀ is measured, and then the coefficient of extension or stretchability (Cs) is determined by the following equation:

Cs=([L ₁ −L ₀]/L ₀)×100(%)

In this embodiment, since the inner upper portion 20 is composed of the body portion 20A of low stretchability and the stretch portion 20B of high stretchability, the inner upper portion 20 itself is set at the tensile testing machine and for example, the tensile load is applied to the inner upper portion 20 in the foot-width direction. The coefficient of extension or stretchability (Cs) of the inner upper potion 20 is preferably 150-200(%), and in the present embodiment, for example, 180(%) is adopted.

Then, the effects of the present embodiment will be explained.

According to the upper structure 2 of the present embodiment, in the upside-down state (see FIG. 7), there is formed a clearance e between the external surface 20 s of the inner upper portion 20 and the internal surface 21 s of the outer upper portion 21 at the toe part (or the front of the forefoot part F). Also, the perimeter 20L of the external surface 20 s of the inner upper portion 20 is smaller than the perimeter 21L of the internal surface 21 s of the outer upper portion 21. Moreover, in the developed state (see FIG. 15), the foot-width measurement w₁ of the inner upper portion 20 is smaller than he foot-width measurement W₁ of the outer upper portion 21. Thereby, the inner upper portion 20 is stretchable inside the outer upper portion 21 at the toe part.

Likewise, in the upside-down state (see FIGS. 8 and 9), there is respectively formed a clearance e₁, e₂ between the medial and lateral side parts 21 ₁, 21 ₂ of the outer upper portion 21 and the inner upper portion 20 at the forefoot part F and the midfoot part M. At this juncture, in the state that the shoelace 11 is inserted into the eyelets 2 a (see FIGS. 8A, 9A), at the medial side part, the perimeter 20 ₁L of the external surface 20 s of the inner upper portion 20 (that is, the perimeter 20 ₁L is the circumferential length measured along the external surface 20 s from the lower end 20 t as a starting end to the position as a terminal end at which the upper end 21 ₁t′ of the medial-side part 21 ₁ of the outer upper portion 21 is in contact with the external surface 20 s of the inner upper portion 20, or the horizontal projection position of the upper end 21 ₁t′ onto the external surface 20 s) is smaller than the perimeter 21 ₁L of the internal surface 21 ₁s of the medial-side part 21 ₁ of the outer upper portion 21 (that is, the perimeter 21 ₁L is the circumferential length measured along the internal surface 21 ₁s from the lower end 21 ₁t as a starting end to the upper end 21 ₁t′ as a terminal end). Also, at the lateral side part, the perimeter 20 ₁L of the external surface 20 s of the inner upper portion 20 (that is, the perimeter 20 ₁L is a circumferential length measured along the external surface 20 s from the lower end 20 t as a starting end to the position as a terminal end at which the upper end 21 ₂t′ of the lateral-side part 21 ₂ of the outer upper portion 21 is in contact with the external surface 20 s of the inner upper portion 20, or the horizontal projection position of the upper end 21 ₂t′ onto the external surface 20 s) is smaller than the perimeter 212L of the internal surface 21 ₂s of the lateral-side part 21 ₂ of the outer upper portion 21 (that is, the perimeter 21 ₂L is the circumferential length measured along the internal surface 21 ₂ s from the lower end 21 ₂ t as a starting end to the upper end 21 ₂t′ as a terminal end). Furthermore, in the developed state (see FIG. 15), the foot-width measurement w₂ of the inner upper portion 20 is smaller than the foot-width measurement W₂ of the outer upper portion 21. Thereby, the inner upper portion 20 is stretchable inside the medial-side part 21 ₁ and the lateral-side part 21 ₂ of the outer upper portion 21 at the forefoot part F and the midfoot part M.

In wearing the shoe 1 according to the present embodiment, the inner upper portion 20 stretches in the clearances e, e₁, e₂ at the forefoot part F and the midfoot part M, such that thereby the inner upper portion 20 imparts a pressing force to the forefoot and midfoot regions of the foot, thus improving a fitting property relative to the forefoot and midfoot regions. Also, in this case, since a stretch of the inner upper portion 20 is restricted by the outer upper portion 21 of a low stretchability from the outside, the outer upper portion 21 can improve a supporting property relative to the forefoot and midfoot regions of the foot. In such a manner, the inner upper portion 20 stretches smoothly at a region from the forefoot part F to the midfoot part M, thereby improving fitting and supporting properties relative to the forefoot and midfoot regions of the foot without giving a discomfort to the foot.

Generally, since the individual difference of the perimeter of the foot is greater at the midfoot region than at the forefoot region of the foot, a fitting property of the upper is more important at the midfoot region than at the forefoot region. According to the present embodiment, the inner upper portion 20 can be fitted according to variations of the feet of individuals such as a flat foot, high-arch foot, low-arch foot and the like. Also, in sports shoes, especially indoor sports shoe accompanied by lateral intense movements, a higher supportability is more required at the midfoot region than at the forefoot region, but according to the present embodiment, such a requirement can be satisfied.

Moreover, according to the present embodiment, since the stretch portion 20B has a triangular shape having an apex on the rear-side end 20C of the inner upper portion 20, a stretch of the stretch portion 20B is greater at the midfoot part M than at the forefoot part F (see FIGS. 10 to 13). Thereby, the stretch portion 20B can follow the three-dimensional contour of the midfoot region of the foot.

Furthermore, according to the present embodiment, the inner upper portion 20 is formed of a substantially flat surface at the forefoot part F to the midfoot part M, thus eliminating a level-difference feeling, discomfort and a pressing feeling to the foot and preventing a smooth bending of the foot from being disturbed. Thereby, adhesive and fitting properties relative to the foot can be further improved.

Here, the manufacturing method of the shoe 1 according to the present embodiment will be briefly explained.

In this case, first, the material for the inner upper portion 20 of a stretchability and the material for the outer upper portion 21 of a lower stretchability than the inner upper portion 20 are prepared. Then, in the developed state of the inner and outer upper portions 20 and 21, the respective materials are cut in such a way that the foot-width measurement of the inner upper portion 20 is smaller than the foot-width measurement of the outer upper portion 21 (see FIG. 15).

Secondly, the outer circumferential edge part of the inner upper portion 20 is sewn to the outer circumferential edge part of the outer upper portion 21 to assemble the upper structure 2. Then, the assembled upper structure 2 is put on the last (not shown) for the shoe. At this time, the inner upper portion 20 stretches on the last. From this state, the midsole 3 is fixedly attached to the bottom part of the upper sole structure 2 and the outsole 4 is bonded to the bottom surface of the midsole 3.

Thereafter, the upper structure 2 is removed from the last. Then, the inner upper portion 20 that has been in a stretched state contracts to return to the original state prior to the stretched state. As a result, a clearance is generated between the inner upper portion 20 and the outer upper portion 21. In such a manner, the shoe 1 is completed.

The variants or alternative embodiments of the present invention will be described hereinafter. In the respective drawings showing the alternative embodiments, like reference numbers indicate identical or functionally similar elements to those in the above-mentioned first embodiment.

First Alternative Embodiment

In the above-mentioned embodiment, an example was shown in which the rearmost end 20Bb of the stretch portion 20B is disposed at a position closer to the front end of the heel part H (see FIGS. 4, 5, 10-13), but the application of the present invention is not restricted to such an example. The rearmost end 20Bb of the stretch portion 20B may be disposed at a position closer to the rear end of the heel part H, for example, at the bottom portion of the calcaneus CA (see FIGS. 12, 13).

Second Alternative Embodiment

In the above-mentioned embodiment, an example was shown in which the clearances e₁, e₂ are respectively formed between the medial-side and lateral-side parts 21 ₁, 21 ₂ of the outer upper portion 21 and the inner upper potion 20 (see FIGS. 8, 9, 8A, 9A), but only either one of these clearances e₁, e₂ may be formed.

Third Alternative Embodiment

In the above-mentioned embodiment, an example was shown in which the perimeter 20 ₁L of the external surface 20 s of the inner upper portion 20 is smaller than the perimeter 21 ₁L of the internal surface 21 ₁S of the medial-side part 21 ₁ of the outer upper portion 21, and the perimeter 20 ₂L of the external surface 20 s of the inner upper portion 20 is smaller than the perimeter 21 ₂L of the internal surface 21 ₂S of the lateral-side part 21 ₂ of the outer upper portion 21 (see FIGS. 8, 9, 8A, 9A), but the application of the present invention is not limited to such an example. Such a size relation of the perimeters of the inner upper portion 20 and the outer upper portion 21 may be satisfied at only either one of the medial-side part 21 ₁ and the lateral-side part 21 ₂ of the outer upper portion 21.

Fourth Alternative Embodiment

In the above-mentioned embodiment, an example was shown in which the body portion 20A of the inner upper portion 20 is formed of one material or cloth (see FIG. 15), but the application of the present invention is not restricted to such an example. FIGS. 16 and 17 illustrate variants of the inner upper portion 20 and respectively correspond to FIG. 15.

As shown in FIG. 16, the body portion 20A of the inner upper portion 20 is composed of three parts divided in the foot-width direction and the foot-length direction, a front part 20A₁ disposed on the front side and a pair of rear parts 20A₂, 20A₃ disposed on the rear side. The rear-side end 20 a ₁ of the front part 20A₁ is formed linear. The rear part 20A₂ has a body portion 20Ai and a stretch portion 20Bi integrally connected to the body portion 20Ai. Likewise, the rear part 20A₃ has a body portion 20Ao and a stretch portion 20Bo integrally connected to the body portion 20Ao. The front-side end 20 a ₂ of the body portion 20Ai and the front-side end 20 a ₃ of the body portion 20Ao are formed linear. The foot-dorsum top end 20 ci of the body portion 20Ai and the foot-dorsum top end 20 co of the body portion 20Ao are formed curved, in this example, convex-arc-shaped or convexly curved.

When assembling the inner upper portion 20 that are composed as mentioned above, the front-side end 20 a ₂ of the body portion 20Ai and the front-side end 20 a ₃ of the body portion 20Ao are sewn to the rear-side end 20 a ₁ of the front part 20A₁, and the convexly curved foot dorsum top end 20 ci of the body portion 20Ai and the convexly curved foot dorsum top end 20 co of the body portion 20Ao are sewn to one another with the respective ends aligned. Sewing here is conducted by a flat sewing such as an abutting-sewing or the like that was explained in the above-mentioned embodiment.

In the assembled inner upper portion 20, the boundary part between the body portions 20Ai and 20Ao at the foot-dorsum top end extends longitudinally linearly as viewed from above and convexly curved as viewed from the side. Thereby, the body portion 20A of the inner upper portion 20 can be formed in a three-dimensional shape, such that thereby the body portion 20A can follow the contour of the three-dimensional shape of the foot. Also, since the inner upper portion 20 is preformed in a three-dimensional shape by the body portion 20A prior to wearing the shoe 1, an entry of the foot into the access opening 10 of the upper structure 2 is made easy thus facilitating wearing of the shoe 1.

FIG. 17 is similar to FIG. 16 in that the body portion 20A of the inner upper portion 20 is composed of three parts, the front part 20A₁ and the rear parts 20A₂, 20A₃, but in this example, the curved shape of the foot-dorsum top end 20 ci of the body portion 20Ai and the foot-dorsum top end 20 co of the body portion 20Ao are different from those of FIG. 16. In FIG. 16, both of the foot-dorsum top end 20 ci of the body portion 20Ai and the foot-dorsum top end 20 co of the body portion Ao are formed of the convex-arc shape (or the convexly curved surface), but in this example, both of the foot-dorsum top end 20 ci of the body portion 20Ai and the foot-dorsum top end 20 co of the body portion Ao are formed of a composite curve combined by the convex-arc shape (or the convexly curved surface) and the concave-arc shape (or the concavely curved surface).

In the assembled inner upper portion 20, the boundary part between the body portions 20Ai and 20Ao at the foot-dorsum top end extends longitudinally linearly as viewed from above, convexly curved as viewed from the side on the front side, and concavely curved as viewed from the side on the rear side. Thereby, the body portion 20A of the inner upper portion 20 can be formed in a three-dimensional shape, such that thereby the body portion 20A can follow the contour of the three-dimensional shape of the foot. Also, since the inner upper portion 20 is preformed in a three-dimensional shape by the body portion 20A prior to wearing the shoe 1, especially, the rear-side end portion of the foot-dorsum top portion of the inner upper portion 20 is formed extending upwardly, an entry of the foot into the access opening 10 of the upper structure 2 is made easier thus further facilitating wearing of the shoe 1.

In the examples shown in FIGS. 16 and 17, since the body portion 20A is made in a three-dimensional shape after the respective parts are sewn to assemble the inner upper portion 20, the inner upper portion 20 cannot be in the state developed on a plane. However, even in that case, when the outer upper portion 21 is disposed outside the inner upper portion 20 to assemble the upper structure 2, a clearance e₁ is formed between the medial-side part 21 ₁ of the outer upper portion 21 and the rear part 20A₂ of the inner upper portion 20, a clearance e₂ is formed between the lateral-side part 21 ₂ of the outer upper portion 21 and the rear part 20A₃ of the inner upper portion 20, the perimeter 20 ₁L of the external surface 20 s of the rear part 20A₂ of the inner upper portion 20 is smaller than the perimeter 21 ₁L of the internal surface 21 ₁S of the medial-side part 21 ₁ of the outer upper portion 21, and the perimeter 20 ₂L of the external surface 20 s of the rear part 20A₃ of the inner upper portion 20 is smaller than the perimeter 21 ₂L of the internal surface 21 ₂S of the lateral-side part 21 ₂ of the outer upper portion 21.

Additionally, this is not shown, but both of the foot-dorsum top end 20 ci of the body portion 20Ai and the foot-dorsum top end 20 co of the body portion 20Ao may be formed of only the concave-arc surface (or concavely curved surface). Also, the way of combination of the convex-arc surface (or convexly curved surface) and the concave-arc surface (or concavely curved surface) is not restricted to that of FIG. 17. Moreover, FIGS. 16 and 17 show an example in which the body portion 20A of the inner upper portion 20 is formed of three parts, but the number of divided parts may be two, or four or more. Also, the position of dividing the body portion 20A of the inner upper portion 20 is not restricted to that shown in FIGS. 16 and 17.

Fifth Alternative Embodiment

FIGS. 18 to 20 respectively show variants of FIG. 15. In those variants, like reference numbers indicate identical or functionally similar elements to those in FIG. 15.

The example shown in FIG. 18 differs from the example shown in FIG. 15 in that the lower-side end (i.e. the sole-side end) of each of the stretch portions 20B of the inner upper portion 20 and the lower-side end (i.e. the sole-side end) of the body portion 20A do not coincides with one another and the body portion area 20Aa is formed between the lower-side end of each of the stretch portions 20B and the lower-side end of the body portion 20A. The example shown in FIG. 19 differs from the example shown in FIG. 15 in that each of the stretch portions 20B of the inner upper portion 20 has a generally rectangular in shape or a generally belt-shape. Also, the shape of the stretch portion 20B is not restricted to a generally triangular-shape shown in FIG. 15 and a generally rectangular-shape or belt-shape shown in FIG. 19. The shapes other than those shapes (e.g. polygonal, elliptical, oval, etc.) may be adopted. The example shown in FIG. 20 differs from FIG. 15 in that the stretch portion 20B is not coupled to the body portion 20A. In this case, the body portion 20A may be composed of mesh material of stretchability, elastic fibers or the like, and has a stretchability as a whole.

Sixth Alternative Embodiment

FIG. 21 shows a variant of FIG. 9. Like reference numbers indicate identical or functionally similar elements to those in FIG. 9. In the example shown in FIG. 21, the respective lower ends 20 t of the body portion 20A of the inner upper portion 20 are not located at the positions of the lower end 21 ₁t of the medial-side part 21 ₁ and the lower end 21 ₂ t of the lateral-side part 21 ₂ of the outer upper portion 21, but fixedly attached to the positions apart from the lower end 21 ₁ t of the medial-side part 21 ₁ and the lower end 21 ₂t of the lateral-side part 21 ₂ of the outer upper portion 21.

In this case too, there are respectively formed clearance e₁, e₂ between the medial-side and lateral-side parts 21 ₁, 21 ₂ of the outer upper portion 21 and the inner upper portion 20.

Seventh Alternative Embodiment

In the above-mentioned embodiment, the example was shown in which the foot-width measurement w of the inner upper portion 21 is smaller than the foot-width measurement W of the outer upper portion 21 in the state that the inner upper portion 20 and the outer upper portion 21 are developed on the same plane (see para. [0063] and FIG. 15), but the application of the present invention is not limited to such an example.

FIGS. 22 to 26 show a seventh alternative embodiment of the present invention. In these drawing, like reference numbers indicate identical or functionally similar elements to those in the above-mentioned first embodiment. In this seventh embodiment, the inner upper portion and the outer upper portion are divided on the longitudinal centerline along the foot-dorsum top portion and composed of a medial-side part and a lateral-side part, respectively.

FIG. 22 is a developed view in which the respective lateral-side parts of the inner upper portion and the outer upper portion are developed on the plane. FIG. 23 is a developed view in which the respective medial-side parts of the inner upper portion and the outer upper portion are developed on the plane. In FIGS. 22 and 23, the developed view of the last is also shown in which the lateral-side/medial-side parts of the last is developed on the plane. FIG. 24 is a developed view in which the respective lateral-side parts of the inner and outer upper portions and the last (FIG. 22) and the respective medial-side parts of the inner and outer upper portions and the last (FIG. 23) are disposed opposite one another such that the respective upper end portions are contraposed, illustrating the state before sewing of the respective upper end portions of the inner and outer upper portions. FIG. 25 is a cross sectional view of the forefoot part in which the respective upper end portions of the lateral-side and medial-side parts of the inner and outer upper portions of the upper structure (FIG. 24) are sewn together, thereafter the upper structure is put on the last and the respective lower edges of the lateral-side and medial-side parts are sewn on the insole board. FIG. 26 is a cross sectional view of the midfoot part in which the respective upper end portions of the lateral-side and medial-side parts of the inner and outer upper portions of the upper structure (FIG. 24) are sewn together, thereafter the upper structure is put on the last and the respective lower edges of the lateral-side and medial-side parts are sewn on the insole board. In FIGS. 25 and 26, the upper structure is shown in the upside-down state.

As shown in FIG. 22, the lateral-side part 20 o (see bold line) of the inner upper portion includes a body portion 20Ao disposed to cover the generally entire region of the lateral side of the foot dorsum of the wearer, and a stretch portion 20Bo (see gray region) of a stretchability disposed below and integrally connected with the body portion 20Ao. The disposition area of the stretch portion 20Bo is similar to that of the above-mentioned embodiment. The lateral-side part 21 o (see dash-and-dot line) of the outer upper portion is disposed outside (or out of the page) of the lateral-side part 20 o of the inner upper portion, has a throat portion 10 a, and extends rearwardly to the heel part overlappingly with the lateral-side part 20 o of the inner upper portion. The lateral-side part 20 o of the inner upper portion has a stretchability or elasticity as a whole due to the stretch portion 20Bo, but the lateral-side part 21 o of the outer upper portion does not have a stretch portion, such that thereby stretchability of the lateral-side part 21 o of the outer upper portion is smaller than that of the lateral-side part 20 o of the inner upper portion.

As shown in FIG. 23, the medial-side part 20 i (see bold line) of the inner upper portion includes a body portion 20Ai disposed to cover the generally entire region of the medial side of the foot dorsum of the wearer, and a stretch portion 20Bi (see gray region) of a stretchability disposed below and integrally connected with the body portion 20Ai. The disposition area of the stretch portion 20Bi is similar to that of the above-mentioned embodiment. The medial-side part 21 i (see dash-and-dot line) of the outer upper portion is disposed outside (or out of the page) of the medial-side part 20 i of the inner upper portion, has a throat portion 10 a, and extends rearwardly to the heel part overlappingly with the medial-side part 20 i of the inner upper portion. The medial-side part 20 i of the inner upper portion has a stretchability or elasticity as a whole due to the stretch portion 20Bi, but the medial-side part 21 i of the outer upper portion does not have a stretch portion, such that thereby stretchability of the medial-side part 21 i of the outer upper portion is smaller than that of the medial-side part 20 i of the inner upper portion.

In FIG. 22, the outer circumferential edge portion (see dash-and-dot line) of the lateral-side part 21 o of the outer upper portion coincides with the outer circumferential edge portion (see bold line) of the lateral-side part 20 o of the inner upper portion except for the throat portion 10 a and the heel part. Likewise, in FIG. 23, the outer circumferential edge portion (see dash-and-dot line) of the medial-side part 21 i of the outer upper portion coincides with the outer circumferential edge portion (see bold line) of the medial-side part 20 i of the inner upper portion except for the throat portion 10 a and the heel part. That is to say, at the front-end-side part of the forefoot part (or the area including the toe portion), the upper edge parts of the lateral-side part 21 o and the medial-side part 21 i of the outer upper portion coincide with or conform to the upper edge parts of the lateral-side part 20 o and the medial-side part 20 i of the inner upper portion, respectively. Also, at a region extending from the forefoot part to the midfoot part, the lower edge parts of the lateral-side part 21 o and the medial-side part 21 i of the outer upper portion coincide with or conform to the lower edge parts of the lateral-side part 20 o and the medial-side part 20 i of the inner upper portion, respectively.

Here, the foot-width measurement wo₁ (see FIG. 22) of the forefoot part of the lateral-side part 20 o of the inner upper portion plus the foot-width measurement wi₁ (see FIG. 23) of the forefoot part of the medial-side part 20 i of the inner upper portion is the foot-width measurement w₁ of the forefoot part of the inner upper portion. Also, the foot-width measurement Wo₁ (see FIG. 22) of the forefoot part of the lateral-side part 21 o of the outer upper portion plus the foot-width measurement Wi₁ (see FIG. 23) of the forefoot part of the medial-side part 21 i of the outer upper portion is the foot-width measurement W₁ of the forefoot part of the outer upper portion. In this seventh alternative embodiment, as can be seen from FIGS. 22 and 23, at the forefoot part,

wo ₁ =Wo ₁ and wi ₁ =Wi ₁

Therefore,

wo ₁ +wi ₁ =Wo ₁ +Wi ₁

Accordingly,

w ₁ =W ₁

That is different from the above-mentioned first embodiment.

As shown in FIG. 22, the lower-side edge portion of the lateral-side part 20 o of the inner upper portion and the lower-side edge portion of the lateral-side part 21 o of the outer upper portion extend further downwardly from the lower-side edge portion of the lateral-side part Lao (see thin line) of the last and such an extension portion Pr is shown by a hatched area. As shown in FIG. 23, the lower-side edge portion of the medial-side part 20 i of the inner upper portion and the lower-side edge portion of the medial-side part 21 i of the outer upper portion extend further downwardly from the lower-side edge portion of the medial-side part Lai (see thin line) of the last and such an extension portion Pr is shown in a hatched area. These extension portions Pr are provided so that the inner and outer upper portions 20, 21 can go around the bottom surface of the last when the inner upper portion 20 and the outer upper portion 21 are put on the last at the time of assembling the shoe.

Also, as shown in FIG. 22, when the foot-width measurement of the forefoot part of the lateral-side part Lao of the last is set to Lo₁, the corresponding foot-width measurement do₁ of the lateral-side part 20 o of the inner upper portion and the corresponding foot-width measurement Do₁(=do₁) of the lateral-side part 21 o of the outer upper portion are smaller than the foot-width measurement Lo₁ of the forefoot part of the lateral-side part Lao of the last. That is,

do ₁ <Lo ₁ and Do ₁ <Lo ₁

Similarly, as shown in FIG. 23, when the foot-width measurement of the forefoot part of the medial-side part Lai of the last is set to Li₁, the corresponding foot-width measurement di₁ of the medial-side part 20 i of the inner upper portion and the corresponding foot-width measurement Di₁(=di₁) of the medial-side part 21 i of the outer upper portion are smaller than the foot-width measurement Li₁ of the forefoot part of the medial-side part Lai of the last. That is,

di ₁ <Li ₁ and Di ₁ <Li ₁

Moreover, as shown in FIG. 22, when the foot-width measurement of the midfoot part of the lateral-side part Lao of the last is set to Lo₂, the corresponding foot-width measurement do₂ of the lateral-side part 20 o of the inner upper portion is smaller than the foot-width measurement Lo₂ of the midfoot part of the lateral-side part Lao of the last. That is,

do ₂ <Lo ₂

Similarly, as shown in FIG. 23, when the foot-width measurement of the midfoot part of the medial-side part Lai of the last is set to Li₂, the corresponding foot-width measurement di₂ of the medial-side part 20 i of the inner upper portion is smaller than the foot-width measurement Li₂ of the midfoot part of the medial-side part Lai of the last. That is,

di ₂ <Li ₂

As shown in FIG. 24, in the state that the respective lateral-side parts (see FIG. 22) of the inner and outer upper portions and the respective medial-side parts (see FIG. 23) of the inner and outer upper portions are contraposed with the respective upper edge portions disposed opposite one another, the respective upper edge portions of the lateral-side and medial-side parts of the inner upper portion are sewn together and the respective upper edge portions of the lateral-side and medial-side parts of the outer upper portion are sewn together. Thereafter, the sewn inner and outer upper portions are put on the last La (see FIGS. 25 and 26). Then, the lower ends 20 t of the medial-side and lateral-side parts of the inner upper portion and the lower ends 21 t of the medial-side and lateral-side parts of the outer upper portion are fixedly attached to the end portion of the insole board 20 through bonding, stitching and the like.

At this juncture, as shown in FIG. 25, at the forefoot part, the external surface 20 s of the inner upper portion 20 composed of the lateral-side part 20 o and the medial-side part 20 i is closely contacted with the internal surface 21 s of the outer upper portion 21 composed of the lateral-side part 21 o and the medial-side part 21 i and there are no clearances formed between the surfaces 20 s and 21 s. The last La comprises a generally planar bottom surface Lab, a medial-side surface Lai extending upwardly (or downwardly in FIG. 25) from the medial-side end of the bottom surface Lab, and a lateral-side surface Lao extending upwardly (or downwardly in FIG. 25) from the lateral-side end of the bottom surface Lab. The bottom surface Lab has a region corresponding to the respective extension portions Pr of the inner upper portion 20 and the outer upper portion 21. The medial-side surface Lai and the lateral-side surface Lao are smoothly connected to one another at the foot-dorsum top portion. The internal surface of the inner upper portion 20 is circumferentially in contact with the external surface of the last La, that is, the medial-side surface Lai and the lateral-side surface Lao.

As shown in FIG. 26, at the midfoot part, the inner upper portion 20 (and the medial-side part 21 ₁ and lateral-side part 21 ₂ of the outer upper portion 21) is in the free-length state such that it extends vertically (or downwardly in FIG. 26) via its self-weight without slackening. At this time, there is respectively formed a clearance e₁, e₂ between the medial-side and lateral-side parts 21 ₁, 21 ₂ of the outer upper portion 21 and the inner upper portion 20. The respective extension portions Pr of the inner upper portion 20 contact the bottom surface Lab of the last La and the internal surface of the inner upper portion 20 contacts the external surface of the last La circumferentially, i.e. the medial-side surface Lai and the lateral-side surface Lao of the last La.

Next, the manufacturing method of the upper sole structure 2 will be briefly explained.

First, the material for the inner upper portion 20 and the material for the outer upper portion 21 are respectively prepared. They are cut and properly sewn together to prepare the lateral-side part 20 o of the inner upper portion 20 formed of the body portion 20Ao and the stretch portion 20Bo, the medial-side part 20 i of the inner upper portion 20 formed of the body portion 20Ai and the stretch portion 20Bi, and the lateral-side part 21 o and the medial-side part 21 i of the outer upper portion 21 (see FIGS. 22 and 23).

Secondly, the respective upper edge portions of the body portion 20Ao of the lateral-side part 20 o and the body portion 20Ai of the medial-side part 20 i of the inner upper portion 20 are contraposed (see FIG. 24) and sewn together to manufacture the inner upper portion 20. The respective upper edge portions of the lateral-side part 21 o and the medial-side part 21 i of the outer upper portion 21 are contraposed (see FIG. 24) and sewn together to manufacture the outer upper portion 21. The lower edge portion of the lateral-side part 20 o of the inner upper portion 20 and the lower edge portion of the lateral-side part 21 o of the outer upper portion 21 are sewn together and the lower edge portion of the medial-side part 20 i of the inner upper portion 20 and the lower edge portion of the medial-side part 21 i of the outer upper portion 21 are sewn together to constitute the upper portion of the upper structure 2.

Then, the assembled upper structure 2 is put on the last (see FIGS. 25 and 26). At this time, the inner upper portion 20 is stretched by the last La, such that thereby the internal surface of the inner upper portion 20 closely contacts the external surface of the last La. In such a state, the insole board 30 is disposed on the bottom surface Lab of the last La and the lower end 20 t of the inner upper portion 20 and the lower end 21 t of the outer upper portion 21 are fixedly attached to the outer circumferential edge portion of the insole board 30 via stitching and the like (see FIGS. 25 and 26). In such a manner, the upper structure 2 is completed. Thereafter, the midsole 3 and the outsole 4 are bonded to the lower portion of the insole board 30 of the upper structure 2 to complete the shoe 1.

As described above, in the upper structure 2, the inner upper portion 20 has the stretch portions 20Bi, 20Bo on the medial side and the lateral side, respectively. The foot-width measurement do₁ of the lateral-side part 20 o of the inner upper portion 20 and the foot-width measurement Do₁ of the lateral-side part 21 o of the outer upper portion 21 are smaller than the foot-width measurement Lo₁ of the forefoot part of the lateral-side part Lao of the last La (do₁<Lo₁, Do₁<Lo₁) (see FIG. 22). The foot-width measurement di₁ of the medial-side part 20 i of the inner upper portion 20 and the foot-width measurement Di₁ of the medial-side part 21 i of the outer upper portion 21 are smaller than the foot-width measurement Li₁ of the forefoot part of the medial-side part Lai of the last La (di₁<Li₁, Di₁<Li₁) (see FIG. 23). The foot-width measurement do₂ of the lateral-side part 20 o of the inner upper portion 20 is smaller than the foot-width measurement Lo₂ of the midfoot part of the lateral-side part Lao of the last La (do₂<Lo₂) (see FIG. 22). The foot-width measurement di₂ of the medial-side part 20 i of the inner upper portion 20 is smaller than the foot-width measurement Li₂ of the midfoot part of the medial-side part Lai of the last La (di₂<Li₂) (see FIG. 23). Thereby, the inner upper portion 20 is stretchable inside the outer upper portion 21.

Consequently, at the time of wearing the shoe 1, in the same manner as the state that the last La is inserted into the interior of the upper structure 2, the inner upper portion 20 stretches at the forefoot part and the midfoot part. Thereby, the inner upper portion 20 imparts a pressing force to the forefoot region and the midfoot region of the foot thus improving a fitting property relative to the forefoot region and the midfoot region. Moreover, in this case, the outer upper portion 21 of a lower stretchability restricts a stretch of the inner upper portion 20 from the outside, thus improving a supporting property relative to the forefoot region and the midfoot region of the foot. In such a way, the inner upper portion 20 smoothly stretches at a region extending from the forefoot part to the midfoot part (especially, at the midfoot part), thereby enhancing fitting and supporting properties relative to the forefoot part to the midfoot part (especially, the midfoot part) without imparting discomfort.

Eighth Alternative Embodiment

In the seventh alternative embodiment, an example was shown in which at both the forefoot part and the midfoot part, the foot-width measurements of the inner upper portion 20 and the outer upper portion 21 are smaller than the foot-width measurement of the last La (FIGS. 22 and 23), but the application of the present invention is not restricted to such an example.

FIGS. 27 and 28 show the eighth alternative embodiment of the present invention, corresponding respectively to FIGS. 22 and 23 of the seventh alternative embodiment. In this eighth alternative embodiment, as shown in FIG. 27, the lower-side edge portion of the lateral-side part 20 o of the inner upper portion and the lower-side edge portion of the lateral-side part 21 o of the outer upper portion coincide with the lower-side edge portion of the lateral-side part Lao (see thin line) of the last along the entire length of the shoe. The upper-side edge portion of the lateral-side part 20 o of the inner upper portion and the upper-side edge portion of the lateral-side part 21 o of the outer upper portion coincide with the upper-side edge portion of the lateral-side part Lao (see thin line) of the last at the front-end side part (or the region including the toe portion) of the forefoot part. Also, as shown in FIG. 28, the lower-side edge portion of the medial-side part 20 i of the inner upper portion and the lower-side edge portion of the medial-side part 21 i of the outer upper portion coincide with the lower-side edge portion of the medial-side part Lai (see thin line) of the last along the entire length of the shoe. The upper-side edge portion of the medial-side part 20 i of the inner upper portion and the upper-side edge portion of the medial-side part 21 i of the outer upper portion coincide with the upper-side edge portion of the medial-side part Lai of the last at the front-end side part (or the region including the toe portion) of the forefoot part.

Therefore, according to the eighth alternative embodiment, as shown in FIG. 27, the foot-width measurement Lo₁ of the forefoot part of the lateral-side part Lao of the last is equal to the corresponding foot-width measurement do₁ of the lateral-side part 20 o of the inner upper portion and the corresponding foot-width measurement Do₁(=do₁) of the lateral-side part 21 o of the outer upper portion. That is,

do ₁ =Lo ₁ and Do ₁ =Lo ₁

Similarly, as shown in FIG. 28, the foot-width measurement Li₁ of the forefoot part of the medial-side part Lai of the last is equal to the corresponding foot-width measurement di₁ of the medial-side part 20 i of the inner upper portion and the corresponding foot-width measurement Di₁(=di₁) of the medial-side part 21 i of the outer upper portion. That is,

di ₁ =Li ₁ and Di ₁ =Li ₁

On the other hand, as shown in FIG. 27, the foot-width measurement Lo₂ of the midfoot part of the lateral-side part Lao of the last is greater than the corresponding foot-width measurement do₂ of the lateral-side part 20 o of the inner upper portion. That is,

do ₂ <Lo ₂

Similarly, as shown in FIG. 28, the foot-width measurement Li₂ of the midfoot part of the medial-side part Lai of the last is greater than the corresponding foot-width measurement di₂ of the medial-side part 20 i of the inner upper portion. That is,

di ₂ <Li ₂

In such a fashion, according to the eighth alternative embodiment, since the foot-width measurement of the inner upper portion 20 and the outer upper portion 21 is smaller than the foot-width measurement of the last La only at the midfoot part, at the time of wearing the shoe 1, the inner upper portion 20 stretches at the midfoot part, such that thereby the inner upper portion 20 imparts a pressing force to the midfoot region of the foot thus improving the fitting property relative to the midfoot region. Moreover, in this case, since a stretch of the inner upper portion 20 is restricted from the outside by the outer upper portion 21 of a lower stretchability, the outer upper portion 21 can improve a supporting property relative to the midfoot region of the foot. In this way, the inner upper portion 20 smoothly stretches at the midfoot part, thus enhancing fitting and supporting properties relative to the midfoot part without imparting a discomfort to the foot.

Other Alternative Embodiment

The above-mentioned embodiment and the respective alternative embodiments should be considered in all respects only as illustrative and not restrictive. Those skilled in the art to which the invention pertains may make various modifications and other embodiments employing the principles of this invention without departing from its spirit or essential characteristics particularly upon considering the foregoing teachings even if there are no explicit descriptions in the specification.

Other Application

In the above-mentioned embodiment and the respective alternative embodiments, the example was shown in which the present invention was applied to indoor shoes for ball games such as volleyball, handball, and the like, but the present invention is also applicable to indoor shoes for racket games such as tennis, badminton, table tennis (or ping-pong), and the like. Moreover, the present invention can be applied to other sports shoes and shoes.

INDUSTRIAL APPLICABILITY

As above-mentioned, the present invention is useful for an upper structure for a shoe, in particular a sports shoe, especially an indoor shoe, that improves fitting and supporting properties relative to the forefoot region and the midfoot region of the foot of the wearer.

DESCRIPTION OF REFERENCE NUMERALS

-   1: Indoor Shoe (Shoe) -   10: Access Opening -   10 a: Throat Portion -   11: Shoelace (Tightening Member) -   2: Upper Structure -   20: Inner Upper Portion -   20A: Body Portion -   20B: Stretch Portion -   20L, 20L₁, 20L₂: Perimeter of External Surface -   20 i: Medial-side Part of Inner Upper Portion -   20 o: Lateral-side Part of Inner Upper Portion -   20Ai: Medial-side Part of Body Portion -   20Ao: Lateral-side Part of Body Portion -   20Bi: Medial-side Part of Stretch Portion -   20Bo: Lateral-side Part of Stretch Portion -   21: Outer Upper Portion -   21 ₁: Medial-side Part -   21 ₂: Lateral-side Part -   21L, 21L₁, 21L₂: Perimeter of Internal Surface -   21 i: Medial-side Part of Outer Upper Portion -   21 o: Lateral-side Part of Outer Upper Portion -   La: Last -   Lai: Medial-side Part of Last -   Lao: Lateral-side Part of Last -   e, e₁, e₂: Clearance -   w₁, w₂: Foot-width Measurement of Inner Upper Portion -   W₁, W₂: Foot-width Measurement of Outer Upper Portion -   Lo₁, Lo₂: Foot-width Measurement of Lateral-side Part of Last -   Li₁, Li₂: Foot-width Measurement of Medial-side Part of Last -   do₁, do₂: Foot-width Measurement of Lateral-side Part of Inner Upper     Portion -   di₁, di₂: Foot-width Measurement of Medial-side Part of Inner Upper     Portion -   Do₁: Foot-width Measurement of Lateral-side Part of Outer Upper     Portion -   Di₁: Foot-width Measurement of Medial-side Part of Outer Upper     Portion -   F: Forefoot Part -   M: Midfoot Part

PRIOR ART REFERENCES Patent Documents <Patent Document 1>

U.S. Pat. No. 4,438,574 (see lines 32-39 of column 4, FIGS. 1-4, lines 11-13, 17-21 and 60-63 of column 3) 

1. An upper structure for a shoe comprising: an inner upper portion that has a stretchability, and that is disposed at an inner side of said upper structure, and that has a forefoot part to cover a forefoot region of a foot of a shoe wearer and a midfoot part to cover a midfoot region of the foot; and an outer upper portion that has a stretchability less than the stretchability of said inner upper portion, and that is disposed at an outer side of said upper structure, and that is overlapped with said inner upper portion; wherein said upper structure has at least one feature selected from the group consisting of: a first feature wherein, in an upside-down state in which said upper structure is disposed upside down and said inner upper portion is at a free length in such a way as to hang downwardly without slackening via a self-weight thereof, said inner upper portion has a clearance relative to said outer upper portion at least at said midfoot part, a second feature wherein, in a state in which said inner upper portion and said outer upper portion are developed on a plane, a foot-width measurement of said inner upper portion is smaller than a foot-width measurement of said outer upper portion at least at said midfoot part, and a third feature wherein, in a state in which said inner upper portion, said outer upper portion, and a last for said upper structure are developed on a plane, a foot-width measurement of said inner upper portion that corresponds to a foot-width measurement of the last is smaller than said foot-width measurement of the last at least at said midfoot part. 2-3. (canceled)
 4. The upper structure according to claim 1, having said first feature; wherein a longitudinally extending throat portion is formed opening in connection with a foot entry of said shoe at a foot dorsum top part of said outer upper portion; and wherein in said upside-down state of said upper structure and in the state that an opening end edge portion of said throat portion of said outer upper portion is in contact with an external surface of said inner upper portion, there is formed a clearance at least either between a lateral-side part of said outer upper portion and a lateral-side part of said inner upper portion on a lateral-side of said throat portion, or between a medial-side part of said outer upper portion and a medial-side part of said inner upper portion on a medial-side of said throat portion.
 5. The upper structure according to claim 1, having said first feature; wherein a longitudinally extending throat portion is formed opening in connection with a foot entry of said shoe at a foot dorsum top part of said outer upper portion; and wherein in said upside-down state of said upper structure and in the state that an opening end edge portion of said throat portion of said outer upper portion is in contact with an external surface of said inner upper portion, in a cross section of said forefoot part and said midfoot part of said upper structure, at least either at a medial-side part or at a lateral-side part of said throat portion, the perimeter extending from a bottom end of an internal surface of said outer upper portion to said opening end edge portion of said throat portion is longer than the perimeter extending from a bottom end of an external surface of said inner upper portion to a position in contact with said opening end edge portion of said throat portion.
 6. The upper structure according to claim 1, wherein a longitudinally extending throat portion is formed opening in connection with a foot entry of said shoe at a foot dorsum top part of said outer upper portion and a tightening member for tightening the foot is provided at said throat potion; and wherein said inner upper portion extends circumferentially from a medial-side part through said foot dorsum top part to a lateral-side part at said forefoot part and said midfoot part, and in the state that the outer upper portion is tightened through said tightening member and an opening end edge portion of said throat portion of said outer upper portion is in contact with an external surface of said inner upper portion, said inner upper portion is stretchable inside said outer upper portion.
 7. The upper structure according to claim 1, wherein said stretchability of said inner upper portion is greater at said midfoot part than at said forefoot part.
 8. The upper structure according to claim 1, wherein said inner upper portion has a substantially flat surface at a region extending from said forefoot part to said midfoot part.
 9. The upper structure according to claim 1, wherein said inner upper portion includes a body part and a stretch part having a stretchability and there is no difference in level at a boundary part between said body part and said stretch part.
 10. The upper structure according to claim 1, wherein said inner upper portion includes a body part and a stretch part having a stretchability and said body part is structured in such a way that a plurality of parts divided in a foot-width direction or a foot-length direction are connected to one another.
 11. A shoe comprising said upper structure according to claim 1 and a sole, wherein a bottom portion of said upper structure is fixedly attached to said sole.
 12. A method of manufacturing a shoe that includes an upper and a sole fixedly attached to a bottom part of said upper, wherein said upper comprises an inner upper portion having a stretchability, wherein said inner upper portion is disposed at an inner side of said upper, and includes a forefoot part to cover a forefoot region of a foot of a shoe wearer and a midfoot part to cover a midfoot region of the foot, wherein said upper further comprises an outer upper portion having a stretchability less than the stretchability of said inner upper portion, and wherein said outer upper portion is disposed at an outer side of said upper and is overlapped with said inner upper portion, said method comprising the steps: preparing said inner upper portion and said outer upper portion; assembling said upper by sewing said outer upper portion onto an outer periphery edge of said inner upper portion; putting said upper on a last for said shoe to stretch said inner upper portion, and fixedly attaching said sole to a bottom part of said upper; and removing said upper from said last to cause said inner upper portion, which has been in a stretched state, to contract and return to an unstretched state that existed prior to the stretched state, such that thereby a clearance is formed between said inner upper portion and said outer upper portion.
 13. The method according to claim 12, wherein in the state that said inner upper portion, said outer upper portion and said last are developed on a plane, a foot-width measurement of said inner upper portion that corresponds to a foot-width measurement of said last is smaller than said foot-width measurement of said last at least at said midfoot part.
 14. The upper structure according to claim 1, having said first feature.
 15. The upper structure according to claim 1, having said second feature.
 16. The upper structure according to claim 1, having said third feature. 